After graduating from Yale University in 1968, George W. Bush joined the Texas Air National Guard's 147th Fighter Group at Ellington Field, completed Air Force flight training, and served as an F-102 fighter pilot before leaving the Guard in 1973. He received a master's of business administration degree from the Harvard Business School in 1975. Following a career in the oil business and part ownership of the Texas Rangers major league baseball team, Bush was elected Governor of Texas in 1994 and reelected four years later. Inaugurated as the 43rd President of the United States in January 2001, he was the first former Air Guardsman to serve as Commander-In-Chief of the nation's armed forces and only the second son of a former chief executive to assume the responsibilities of the Oval Office. During his first term, he promoted a sweeping revamping of public education, taxes, national defense, Social Security, and Medicare. He was best known for his steadfast leadership of the nation following the terrorist attacks on New York City and the Pentagon with hijacked airliners on September 11th, 2001. After those attacks, which killed some 3,000, Bush reassured the American people with his courage and determination while strengthening the nation's homeland defenses and launching a "Global War on Terrorism." The latter included rapid military victories that toppled the radical Islamic regime in Afghanistan in 2002, which sheltered the Al Qaeda terrorist organization responsible for the September 11th attacks on the U.S. and overthrew Saddam Hussein's brutal Iraqi dictatorship in 2003. Bush was inaugurated for a second term in January 2005. He was the twentieth member of the militia and National Guard to serve as the nation's chief executive.